A dearth of marriagable men has left an “oversupply” of educated women taking desperate steps to preserve their fertility, experts say.

The first global study into egg freezing found that shortages of eligible men were the prime reason why women had attempted to take matters into their own hands.

Experts said “terrifying” demographic shifts had created a “deficit” of educated men and a growing problem of “leftover” professional women, with female graduates vastly outnumbering males in in many countries.

Researchers found that in more than 90 per cent of cases, the women were attempting to buy extra time because they could not find a partner to settle down with, amid a “dearth of educated men”.

Experts said the research bust the myth that “selfish career women” were choosing to out their fertility on ice in a bid to put their careers first.

They said sweeping social changes meant that many professional women now struggled to find a partner that felt like an equal match.

The situation is actually more dire, because it’s not just a question of finding an “equal match”, because women generally prefer their partners to slightly outrank them in status and earnings – though not as much as in China, where three quarters of women want their mates to earn twice as much as they do. As the pool of eligible bachelors shrinks in size relatively to the pool of eligible bachelorettes, something has to give – either the expectations of an “equal or better” match or the expectation of relationship and family.